This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A128151 #4 Feb 15 2022 02:00:17 %S A128151 1,3,2,3,5,3,3,5,7,4,3,5,7,9,5,3,5,7,9,11,6,3,5,7,9,11,13,7,3,5,7,9, %T A128151 11,13,15,8,3,5,7,9,11,13,15,17,9,3,5,7,9,11,13,15,17,19,10 %N A128151 A002260 * A097806. %C A128151 Row sums = A028387: (1, 5, 11, 19, 29, 41, ...). %F A128151 A002260 * A097806 as infinite lower triangular matrices. a(1) = 1; n-th row has (n-1) terms in the sequence (3, 5, 7, 9, ...) followed by "n". %e A128151 First few rows of the triangle: %e A128151 1; %e A128151 3, 2; %e A128151 3, 5, 3; %e A128151 3, 5, 7, 4; %e A128151 3, 5, 7, 9, 5; %e A128151 ... %Y A128151 Cf. A002260, A097806, A028387. %K A128151 nonn,tabl %O A128151 1,2 %A A128151 _Gary W. Adamson_, Feb 16 2007